Display apparatus

ABSTRACT

The present invention relates to a display apparatus comprising front display unit ( 10 ) and rear display unit ( 50 ), wherein the front display unit ( 10 ) and the rear display unit ( 50 ) are arranged such that an image on the rear display unit ( 50 ) is visible through a portion of the front display unit ( 10 ). The front display unit ( 10 ) comprise: a display panel ( 20 ); a front backlight ( 30 ) which is arranged behind the display panel ( 20 ), and which includes a first light guide plate ( 36 ) having a projection window ( 16 ) through which an image on the rear display unit ( 50 ) is visible, first light sources ( 38 ) arranged along the circumference of the first light guide plate ( 36 ), and a reflection sheet ( 39 ) arranged at the rear surface of the first light guide plate ( 36 ) to reflect light and having an image hole ( 18 ) formed at the region thereof that corresponds to the projection window ( 16 ); a rear backlight ( 40 ) arranged behind the front backlight ( 30 ) and including a second light guide plate ( 42 ) corresponding to the projection window ( 16 ) and second light sources ( 44 ) arranged along the circumference of the second light guide plate ( 42 ); and a rear optical shutter ( 48 ) arranged behind the second light guide plate ( 24 ). The rear optical shutter ( 48 ) is made of a transparent material, such that the rear display unit and the front display unit cooperate with one another to display a combined image. The entire screen of the front display unit is capable of displaying an image, without any disconnection of the image, when the rear optical shutter is closed.

TECHNICAL FIELD

The present invention relates to a display apparatus which includesfront and rear display units cooperating with each other to display acombined image and, more particularly, to a display apparatus whichpermits a front display unit to display an image on an entire screenthereof without disconnection of the screen.

BACKGROUND ART

Generally, in a slot machine using a rotational reel display unit, aliquid crystal display is used to induce interest in a game and displaymore colorful images. Typically, the liquid crystal display is disposedon a front side of the game machine, and an opening is formed on a lightguide plate constituting a backlight unit of the liquid crystal display.Further, the opening is provided at the rear thereof with a rotationalreel on which a reel band having symbol marks is mounted. With thisconfiguration, a rear rotational reel display unit is viewed through theopening of the light guide plate and a game-related image is displaythrough the liquid crystal display at the front side of the gamemachine, thereby inducing interest in the game.

However, in such a game machine, light is not emitted through theopening of the light guide plate, causing disconnection of an imagedisplayed on the liquid crystal display. For example, when agame-related image is displayed through the liquid crystal display atthe front side of the game machine, with the rear rotational reeldisplay unit stopped, it is difficult to display the image since abacklight unit is not present in a region through which the rotationalreel display unit is viewed. As a result, the game machine provides onlya very restrictive and disconnected screen image in displaying gameresults and guide messages through the front liquid crystal display.

Moreover, although the rotational reel display unit at the rear side ofthe game machine is illuminated by a separate lighting lamp, therotational reel display unit is always exposed through the opening ofthe light guide plate even in the case in which the lighting lamp isturned off. This configuration provides a coarse appearance to thedisplay apparatus while a game is not played.

DISCLOSURE Technical Problem

The present invention is conceived to solve such problems in the art,and provides a display apparatus configured to display a combined imagethrough cooperation between front and rear display units, wherein therear display unit may be viewed through a projection window and theentirety of the front display unit may be illuminated to allow the frontdisplay unit to display an image on the entire screen thereof withoutdisconnection of the screen while selectively shielding the rear displayunit, so that the display apparatus may display game results, guidemessages, and other game-related images on the front display unitwithout any restriction and may enhance screen display quality even whena game is not played.

In addition, the present invention provides a display apparatus whichmay selectively shield the front display unit in order to indicatewhether a game is played or not.

Further, the present invention provides a display apparatus in which alight guide plate of a front backlight unit is formed with a patternregion and a non-pattern region to provide a projection window withoutcutting the light guide plate, thereby simplifying a manufacturingprocess of the light guide plate, improving brightness of the frontbacklight unit, and suppressing light interference between the frontbacklight unit and the rear backlight unit on the projection window.

Technical Solution

In accordance with one aspect of the present invention, a displayapparatus includes a front display unit 10 and a rear display unit 50disposed behind the front display unit 10 such that an image of the reardisplay unit 50 can be viewed through part of the front display unit 10,wherein the front display unit 10 includes a display panel 20; a frontbacklight unit 30 including a first light guide plate 36 disposed behindthe display panel 20 and having a projection window 16 through which therear display unit 50 is visible, a first light source 38 arranged alongthe circumference of the first light guide plate 36, and a reflectivesheet 39 placed on a backside of the first light guide plate 36 toreflect light and opened at a region thereof corresponding to theprojection window 16 to form an image hole 18; a rear backlight unit 40including a second light guide plate 42 disposed at a placecorresponding to the projection window 16 behind the front backlightunit 30, and a second light source 44 arranged along the circumferenceof the second light guide plate 42; and a rear optical shutter 48disposed behind the second light guide plate 24

In some embodiments, the rear display unit 50 may be a rotational reeldisplay unit having a plurality of variable image arrays.

In some embodiments, the rear display unit 50 may include one of an LCD,PDP, OLED, and AMOLED.

In some embodiments, the rear display unit 50 may be a picture or anobject displaying an image.

In some embodiments, when the rear display unit 50 is the rotationalreel display unit or the picture or object displaying an image, thedisplay apparatus may further include a rear display lighting unit 56which illuminates the rear display unit 50.

In some embodiments, the display panel 20 may be a liquid crystal panel,which includes a TFT substrate 26, a color filter 24, and liquidcrystals encapsulated between the TFT substrate 26 and the color filter24 bonded to each other.

In some embodiments, the projection window 16 may be formed by cutting apart of the first light guide plate 36 corresponding to the rear displayunit 50.

In some embodiments, the first light guide plate 36 includes a patternregion 36 a formed on a region thereof excluding the projection window16 and having a pattern printed thereon, and a non-pattern region 36 bformed on a region of the projection window 16 and having no pattern.

In some embodiments, the display apparatus further includes a frontoptical shutter 46 disposed behind the display panel 20.

In some embodiments, the front optical shutter 46 and the rear opticalshutter 48 may be liquid crystal shutters including polymer dispersedliquid crystals (PDLC).

In some embodiments, the first and second light sources may be CCFLs orLEDs.

Advantageous Effects

According to the present invention, the front display unit of thedisplay apparatus is equipped with a front backlight unit having aprojection window through which the rear display unit is visible, a rearbacklight unit is placed corresponding to the projection window, and arear optical shutter is placed behind the rear backlight unit. With thisconfiguration, when the rear optical shutter is switched to atransparent state, the rear display unit may be viewed through the lightguide plate of the rear backlight unit to display a combined image incooperation with the front display unit. Further, when the rear opticalshutter is shielded, the rear backlight unit illuminates a region of thefront display unit corresponding to the projection window, with an imageof the rear display unit completely shielded, so that the entirety ofthe front display unit can be illuminated, thereby allowing the frontdisplay unit to display an image on the entire screen thereof withoutdisconnection of the screen. As a result, the display apparatus mayrealize display of game-related images in various ways in higher qualityby allowing the game-related images to be displayed through the entirescreen of the front display unit while completely blocking the reardisplay unit when a game is not played.

In addition, according to the present invention, the display panel isprovided at the rear side thereof with a front optical shutter which isused to switch the front optical shutter to a transparent state or to ashielded state in order to indicate whether a game is played bycontrolling on/off of the overall screen of the display apparatus.

Further, according to the present invention, the light guide plate ofthe front backlight unit is formed with a pattern region and anon-pattern region to provide a projection window without cutting thelight guide plate, thereby simplifying a manufacturing process of thelight guide plate, improving brightness of the front backlight unitthrough an increase in total reflection area within the light guideplate, and suppressing light interference between the front backlightunit and the rear backlight unit by light shielding between the patternregion and the non-pattern region.

Furthermore, such effects of the present invention may be usefullyapplied not only to game machines such as slot machines, but also to atechnique for embodying 3-dimensional and 2-dimensional images based oncombination of front and rear display units, and other image displaytechniques based on combination of the front and rear display units.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a front display unit in accordance withthe present invention;

FIG. 2 is a sectional view of a display apparatus in accordance with oneembodiment of the present invention;

FIG. 3 is a sectional view of a display apparatus in accordance withanother embodiment of the present invention;

FIG. 4 is a front view of a first light guide plate in accordance withanother embodiment of the present invention; and

FIG. 5 is a cross-sectional view of the first light guide plate takenalong line A-A′ of FIG. 4.

<Description of reference numerals of main parts of the drawings > 10:front display unit 12: front backlight unit housing 14: rear backlightunit housing 16: projection window 18: image hole 20: display panel 22:polarizer film 24: color film 26: TFT substrate 28: polarizer film 30:front backlight unit 32: prism sheet 34: diffusive sheet 36: first lightguide plate 36a: pattern region 36b: non-pattern region 38: first lightsource 39: reflective sheet 40: rear backlight unit 42: second lightguide plate 44: second light source 46: front optical shutter 48: rearoptical shutter 50: rear display unit 52: rotational reel 54: reel band56: rear display lighting unit

DESCRIPTION OF PREFERRED EMBODIMENTS

Embodiments of the present invention will now be described in detailwith reference to the accompanying drawings.

The present invention relates to a display apparatus which displays acombined image through cooperation between a front display unit and arear display unit disposed behind the front display unit. Such a displayapparatus may be applied in various ways, for example, game machinessuch as slot machines, game machines which display images throughcombination of front and rear displays, 3D image display apparatuses,electronic frames, and the like.

According to one embodiment, a liquid crystal display and a rotationalreel display unit may be used as front and rear display units,respectively. The rotational reel display unit may be configured toprovide variable display of symbol marks printed on a reel band and toallow winning of a game to be determined according to combination of thesymbol marks.

In another embodiment, the rear display unit may be replaced by othertypes of display unit. For example, typical display apparatuses such asa liquid crystal display (LCD), plasma display panel (PDP), organiclight emitting diode (OLED), active matrix organic light emitting diode(AMOLED), and the like, may be provided as the rear display unit. In afurther embodiment, a picture or an object (for example, jewelry)displaying a certain image may be provided as the rear display unit.

FIG. 1 is a perspective view of one example of a front display unit inaccordance with the present invention, and FIGS. 2 and 3 are schematicviews of display apparatuses in accordance with embodiments of theinvention. Referring to FIG. 1, the front display unit 10 includes adisplay panel 20, a front optical shutter 46, a front backlight unit 30,a rear backlight unit 40, and a rear optical shutter 48 arranged to forma multilayer structure. As shown in FIGS. 2 and 3, a rear display unit50 is placed behind the front display unit 10. FIG. 2 shows a rotationalreel display unit according to one embodiment of the invention and FIG.3 shows a rotational reel display unit according to another embodimentof the invention.

Referring to FIG. 2, when a rotational reel display unit is provided asthe rear display unit 50, the rotational reel display unit has astructure in which a reel band 54 is attached to an outer periphery of arotational reel 52 and is printed with symbol marks (not shown).Further, a rear display lighting unit 56 is placed inside or outside therotational reel 52 to illuminate the symbol marks. Accordingly, the reardisplay unit 50 may be viewed by operating the rear display lightingunit to illuminate the rotational reel 52, and a game result may bedetermined based on a combination of the symbol marks, which may beviewed through the front display unit 10 when rotation of the rotationalreel 52 is stopped.

Referring to FIG. 3, the rear display unit 50 may be realized by adisplay unit such as an LCD, PDP, OLED, AMOLED, and the like. In thiscase, a game-related image is displayed through the display unit at therear side and a gamer views the image corresponding to the game throughthe front display unit 10. Here, since the display unit provided as therear display unit 50 is the same as a typical display apparatus, adetailed description of the display unit including a backlight unit willbe omitted herein.

In the embodiment of FIG. 1, the display apparatus is illustrated asbeing applied to a slot machine, but the display apparatus according tothe present invention may be embodied by a structure in which the frontdisplay unit 10 has a plurality of visible regions and 3D images can bedisplayed through cooperation between the front and rear display units10, 50.

Referring to FIG. 1, the display panel 20 may be a liquid crystal panel.The display panel 20 includes a TFT substrate 26, a color filter 24, andpolarizer films 22, 28 provided to front and rear sides of a panelprovided by bonding the TFT substrate 26 to the color filter 24. As in atypical liquid crystal panel, the TFT substrate 26 is an array substratewhich includes pixel regions and pixel electrodes arranged in a matrix,gate wires, and source wires arranged in transverse and longitudinaldirections, and the color filter 24 is a glass substrate on which R, Gand B patterns are printed or R, G and B films are coated. Although notshown in the drawings, a drive IC is mounted on a lateral side of thepanel provided by bonding the TFT substrate 26 to the color filter 24,and liquid crystals are encapsulated between the TFT substrate 26 andthe color filter 24. Each of the polarizer films 22, 28 is printed withpatterns orthogonal to one another and serves to permit realization ofvarious colors through the color filter by determining penetration andblocking of light when a polarizing direction of the light is changedaccording to movement of the liquid crystals. Although not shown in thedrawings, the display panel 20 may further include other components,such as a protective film, a glass substrate, and the like.

The front optical shutter 46 is placed between the display panel 20 andthe front backlight unit 30. The front optical shutter 46 allows lightfrom the front backlight unit 30 to pass therethrough or blocks thelight therefrom, and may include polymer dispersed liquid crystals(PDLC). The PDLC panel includes liquid crystals dispersed within apolymer without using a polarizer film. When voltage is not applied tothe front optical shutter, the liquid crystals are non-uniformlyarranged in the front optical shutter, so that the front optical shutterblocks light. When voltage is applied thereto, the liquid crystals areuniformly arranged, so that the front optical shutter is switched to atransparent state. With this configuration, the front optical shutter 46blocks light from the front backlight unit 30 and the rear backlightunit 40 described below, thereby forcibly blocking display of the frontdisplay unit 10.

As shown in the drawings, the front backlight unit 30 includes opticalsheets such as a prism sheet 32 and a diffusive sheet 34, a first lightguide plate 36, first light sources 38, and a reflective sheet 39. Theprism sheet 32 is an optical sheet for collecting light and thediffusive sheet 34 is an optical sheet for dispersing light in order toobtain uniform brightness. Such optical sheets may be selectively usedor replaced by other optical sheets. Further, the front backlight unitmay further include a protective sheet and the like. As shown in thedrawings, such optical sheets are partially formed with image holes 18through which the rear display unit 50 is visible.

The first light guide plate 36 receives light from the first lightsources 38 through a thickness plane and emits light through a surfaceof the panel, and is formed of transparent acryl or the like. Each ofthe first light sources 38 may be embodied by a cold cathode fluorescentlamp (CCFL) as shown in FIG. 1, or may be embodied by an LED as shown inFIGS. 2 and 3. Further, the first light sources 38 are disposed atperipheral sides of the first light guide plate 36. In this embodiment,the first light sources 38 are illustrated as being disposed at upperand lower sides of the first light guide plate 36. Alternatively, thefirst light sources 38 may also be disposed at right and left sides ofthe first light guide plate 36.

As shown in the drawings, the first light guide plate 36 is formed withprojection windows 16 through which the rear display unit 50 is visible.The projection windows 16 are non-luminous regions, and light of thefront backlight unit 30 is not generated from regions having theprojection windows 16. Accordingly, it is possible to view the reardisplay unit 50 through the projection windows 16 while a screen isdisplayed on the display panel 20.

Meanwhile, in the embodiment of FIG. 1, the projection windows 16 areformed by cutting three central regions of the first light guide plate36 to form openings on the first light guide plate. However, in someembodiments, the projection windows 16 may be formed without cutting thecentral regions of the first light guide plate 36, and this techniquewill be described below with reference to FIGS. 4 and 5.

The reflective sheet 39 is disposed at the rear of the first light guideplate 36 to reflect light. As in the optical sheets described above, thereflective sheet 39 is opened at three regions corresponding to theprojection windows 16 to form the image holes 18. The reflective sheet39 may be realized by a protective glass which includes a reflectivefilm attached to an overall surface thereof.

In order to allow the front display unit 10 to display an image on anentire screen thereof, the display apparatus according to theembodiments of the present invention further includes a separate rearbacklight unit 40 and a separate rear optical shutter 48 disposed behindthe front backlight unit 30. As shown in FIGS. 2 and 3, the displaypanel 20 and the front backlight unit 30 are placed inside a frontbacklight unit housing 12, and the rear backlight unit 40 and the rearoptical shutter 48 are disposed within a separate rear backlight unithousing 14. Advantageously, the rear backlight unit housing 14 may beassembled to an opening formed on a backside of the front backlight unithousing 12.

The rear backlight unit 40 includes second light guide plates 42 placedcorresponding to the projection windows 16 of the front backlight unit30, and second light sources 44 disposed at peripheral sides of each ofthe second light guide plates 42. Like the first light guide plate 36,the second light guide plates 42 may be realized by transparent panels,and the second light sources 44 may be realized by CCFLs or LEDs.Although the second light sources 44 are illustrated as being disposedat upper and lower sides of the corresponding second light guide plates42, the second light sources 44 may be disposed at right and left sidesof the second light guide plate 42.

Here, in order to achieve the objectives of the present invention, therear backlight unit 40 is configured to illuminate the front displayunit 10 and is viewable. Thus, the rear backlight unit 40 is notprovided at the backside thereof with any reflective sheet. Instead, asshown in the drawings, the rear backlight unit 40 is provided at thebackside thereof with a rear optical shutter 48. Although the rearoptical shutter 48 may be realized by various types of optical devices,the rear optical shutter 48 may be realized by PDLC, as in the frontoptical shutter 46.

When the rear optical shutter 48 is in a transparent state and the rearbacklight unit 40 is turned off, the rear display unit 50 is viewedthrough the second light guide plates 42 of the rear backlight unit 40.As a result, the display apparatus may display a combined image of thefront and rear display units 10, 50. Further, when the rear opticalshutter 48 is in a shielded state and the rear backlight unit 40 isturned on, the rear display unit 50 is completely blocked from a user'sview and the rear backlight unit 40 illuminates the projection windows16 of the front backlight unit 30, so that a clear image may bedisplayed throughout the screen of the front display unit 10.

Although not shown in the drawings, the display apparatus may furtherinclude an optical shutter on the front side of the rear backlight unit40. The optical shutter on the front side of the rear backlight unit 40is operated to completely shield light of the rear backlight unit 40.

FIG. 4 is a front view of a first light guide plate in accordance withanother embodiment of the present invention, and FIG. 5 is across-sectional view of the first light guide plate taken along lineA-A′ of FIG. 4.

Referring to these drawings, in this embodiment, the first light guideplate 36 is formed with projection windows 16 without cutting thecentral regions thereof.

Referring to FIG. 4, the first light guide plate 36 has a pattern region36 a and a non-pattern region 36 b. In the first light guide plate 36, apredetermined pattern is printed only on a region through which the reardisplay unit 50 is not viewed, that is, on a region on which theprojection windows 16 will not be formed. The pattern formed on thepattern region 36 a is typically the same as the pattern printed overthe entire surface of the light guide plate, and serves to collect andrefract light forwards when the light enters the light guide plate. Forexample, the pattern formed on the pattern region 36 a may be a patternof dots arranged in a matrix. Further, brightness of the light guideplate may be determined by adjusting distances between pattern rows andbetween pattern columns. In some embodiments, a combined pattern may beused to improve brightness and light uniformity of the light guideplate.

The non-pattern region 36 b has no pattern and is formed on a region ofthe first light guide plate 36 corresponding to the projection windows16 through which the rear display unit 50 is visible. The non-patternregion 36 b prevents light from being emitted through the front sidethereof by total reflection of the light incident on the first lightguide plate 36. With this configuration, the first light guide plate 36emits light only through the front side of the pattern region 36 awithout emitting light through the front side of the non-pattern region36 b.

Here, total reflection of light occurring within the non-pattern region36 b of the first light guide plate 36 cannot be observed from theoutside, so that the non-pattern region 36 b appears transparent.

In this configuration of the first light guide plate 36, since thecentral region of the light guide plate is not removed, the first lightguide plate 36 may be manufactured by a simple process. Further,compared with the first light guide plate 36, the central regions ofwhich are removed as shown in FIG. 1, the first light guide plate 36according to this embodiment provides an increased total reflectionarea, thereby improving brightness. This effect may reduce overall powerconsumption of the display apparatus through a reduction in powerconsumption of the first light source 38. Further, a light shieldingeffect occurs between the pattern region 36 a and the non-pattern region36 b, thereby significantly suppressing light interference between thefront backlight unit 30 and the rear backlight unit 40.

Although some embodiments have been described herein, it should beunderstood by those skilled in the art that these embodiments are givenby way of illustration only, and that various modifications, variationsand alterations can be made without departing from the spirit and scopeof the invention. Therefore, the scope of the invention should belimited only by the following claims and equivalents thereof.

1. A display apparatus including a front display unit (10) and a reardisplay unit (50) disposed behind the front display unit (10) such thatan image of the rear display unit (50) can be viewed through part of thefront display unit (10), the front display unit (10) comprising: adisplay panel (20); a front backlight unit (0) including a first lightguide plate (36) disposed behind the display panel (20) and having aprojection window (16) through which the rear display unit (50) isvisible, a first light source (38) arranged along the circumference ofthe first light guide plate (36), and a reflective sheet (39) placed ona backside of the first light guide plate (36) to reflect light andopened at a region thereof corresponding to the projection window (16)to form an image hole (18); a rear backlight unit (40) including asecond light guide plate (42) disposed at a place corresponding to theprojection window (16) behind the front backlight unit (30), and asecond light source (44) arranged along the circumference of the secondlight guide plate (42); and a rear optical shutter 48 disposed behindthe second light guide plate (24).
 2. The display apparatus of claim 1,wherein the rear display unit (50) is a rotational reel display unithaving a plurality of variable image arrays.
 3. The display apparatus ofclaim 1, wherein the rear display unit (50) comprises one of an LCD,PDP, OLED, and AMOLED.
 4. The display apparatus of claim 1, wherein therear display unit (50) is a picture or an object which displays animage.
 5. The display apparatus of claim 2, further comprising: a reardisplay lighting unit (56) which illuminates the rear display unit (50).6. The display apparatus of claim 1, wherein the display panel (20) is aliquid crystal panel which comprises a TFT substrate (26), a colorfilter (24), and liquid crystals encapsulated between the TFT substrate(26) and the color filter (24) bonded to each other.
 7. The displayapparatus of claim 1, wherein the projection window (16) is formed bycutting a part of the first light guide plate (36) corresponding to therear display unit (50).
 8. The display apparatus of claim 1, wherein thefirst light guide plate (36) comprises a pattern region (36 a) formed ona region thereof excluding the projection window (16) and having apattern printed thereon, and a non-pattern region (36 b) formed on aregion of the projection window (16) and having no pattern.
 9. Thedisplay apparatus of claim 1, further comprising: a front opticalshutter (46) disposed behind the display panel (20).
 10. The displayapparatus of claim 9, wherein the front optical shutter (46) and therear optical shutter (48) are liquid crystal shutters comprising polymerdispersed liquid crystals (PDLC).
 11. The display apparatus of claim 1,wherein the first and second light sources are CCFLs or LEDs.
 12. Alight guide plate provided to a backlight unit used as a rear lightingunit for a display unit and emitting light through a surface thereofwhen receiving light through a thickness plane, the light guide plate(36) comprising: at least one non-light emitting region through which adisplay apparatus or an object at a rear side is visible, wherein apattern region (36 a) is formed on a region of the light guide plateexcluding the at least one non-light emitting region and has a patternprinted thereon, and a non-pattern region (36 b) is formed on the atleast one non-light emitting region and has no pattern.
 13. The displayapparatus of claim 4, further comprising: a rear display lighting unit(56) which illuminates the rear display unit (50).